Musculoskeletal Flashcards
What is osteoarthritis?
- wear and tear in the synovial joints
- imbalance between cartilage wearing down and chondrocyte repair leading to structural issues
- slow onset
What is the pathophysiology behind osteoarthritis?
- chondrocytes release enzymes
- these break down collagen and proteoglycans
- exposure of underlying subchondral bone leads to sclerosis
- reactive remodelling > osteophytes and subchondral cysts
- joint space lost
What occurs in the joint as OA gets more severe?
- joint space narrows
- cartilage loss
- occurrence and growth of osteophytes
What are the causes and risk factors of OA?
- results from genetic factors, overuse, injury
- RFs: obesity, age, occupation, female, family history
What are the key criteria for diagnosis of OA?
- over 45
- pain with activity
- little to no morning stiffness
Which joints are commonly affected in osteoarthritis?
- affects weight bearing joints
- hip, knee, wrist
- sacroiliac joints
- DIPs in hands
- carpometacarpal joint at base of thumb
- cervical spine
How does osteoarthritis present?
- joint pain and stiffness worse with activity and at end of day
- bulky, bony enlargement of joint
- restricted range of motion
- crepitus when moving
- effusions around joint
What signs of OA are seen in the hands?
- Heberden’s (DIP) and Bouchard’s (PIP) nodes
- squaring at CMC joint
- weak grip
- reduced range of motion
What are the signs of OA in the knee?
- occurs in lateral, patellofemoral or medial (most common) compartments
- occurs without trauma and with slow evolution
What are the 5 key changes seen on X-ray in OA?
- Joint space narrowing
- Osteophyte formation
- Subchondral sclerosis
- Subchondral cysts
- Abnormalities of bone contour
What is the non-medical management of OA?
- patient advice
- weight loss: activity and exercise
- physio, OT, orthotics
- walking aids: stick/frame
How is OA managed?
- analgesia: paracetamol, NSAIDs (+PPI), opiates
- intra-articular steroid injection
- joint replacement last resort
What is systemic sclerosis?
- autoimmune inflammatory and fibrotic connective tissue disease
- affects skin and internal organs
- limited cutaneous or diffuse cutaneous
What are the features of limited cutaneous systemic sclerosis?
- Calcinosis
- Raynaud’s phenomenon
- oEsophageal dysmotility
- Sclerodactyly
- Telangiectasia
What additional problems occur in diffuse systemic sclerosis?
- cardiovascular: htn and coronary artery disease
- lung: pulmonary htn and fibrosis
- renal: glomerulonephritis, renal crisis
What is scleroderma?
- hardening of the skin
- gives shiny, tight appearance without normal folds
- most notably occurs on hands and face
What is sclerodactyly?
- skin changes in the hands
- tightening around the joints
- fat pads on fingers are lost > breaking and ulceration
What is calcinosis and telangiectasia?
- calcinosis: calcium deposits build up under skin (mostly found on fingertips)
- telangiectasia: small dilated blood vessels in skin - fine, thready appearance
Why does Raynaud’s occur in systemic sclerosis?
- vasoconstriction leads to fingers going white > blue in response to mild cold
Which autoantibodies are found in systemic sclerosis?
- antinuclear antibodies
- anti-centromere antibodies (limited)
- anti-Slc-70 antibodies (diffuse)
What is nailfold capillaroscopy?
- where skin meets fingernails is magnified
- abnormal capillaries, avascular areas and micro-haemorrhages indicate systemic sclerosis
How is systemic sclerosis managed?
- steroids and immunosuppressants
- Nifedipine for Raynaud’s
- PPIs and pro-motility meds for GI
- physiotherapy for healthy joints
- skin stretching and gentle emollients
What is rheumatoid arthritis?
- autoimmune condition
- chronic inflammation of synovial lining of joints, tendon sheaths
- affects multiple symmetrical, peripheral joints
What is the epidemiology of RA?
- 3x more common in women than in men
- develops in middle age
- family history increases risk
- HLA DR1 and HLA DR4 gene
Which antibodies are found in RA?
- Rheumatoid factor (IgM) is an autoantibody which targets IgG
- Cyclic citrullinated peptide antibodies (anti-CCP)
How does RA present?
- symmetrical distal polyarthropathy
- pain, swelling and stiffness
- occurs in small joints of hands and feet
- systemic: fatigue, weight loss, flu like, muscle ache
Which joints are most commonly affected in RA?
- PIP
- MCP
- wrist and ankle
- metatarsophalangeal joints
- cervical spine
What signs of RA are seen in the hands?
- Z shaped deformity to thumb
- swan neck deformity (hyperextended PIP and flexed DIP)
- Boutonnieres deformity (hyperextended DIP and flexed PIP)
- ulnar deviation of fingers at knuckle
What investigations are done for RA?
- FBC: anaemia and infection
- ESR and CRP
- RF and anti-CCP
- X-ray of hands and feet
How is RA managed?
- 1st: methotrexate, leflunomide or sulfasalazine
- methotrexate in combination with folic acid
- biological therapy can be added (TNF inhibitor)
- rituximab
What is the pathophysiology of giant cell arteritis?
- no clear margin between media, adventitia and intima
- narrowed lumen
- activated immune cells infiltrate vessel wall > damage and vascular smooth muscle cell remodelling
- leads to weakening and occlusion of vessels
- leading to ischaemia, infarction, aneurysm
What is the aetiology of vasculitis?
- 1º: idiopathic autoimmune process
- 2º: drugs, infection, other autoimmune disease
- immune complex or ANCA mediated
What are types of large vessel arteritis?
- giant cell arteritis
- Takayasu arteritis
What are type of medium vessel arteritis?
- Kawasaki disease (coronary in children)
- polyarteritis nodosa (adults)
What are examples of small vessels ANCA +ve vasculitis?
- small arteries, veins
- microscopic polyangitis
- Wegner’s (granulomatosis with polyangitis)
- Churg-Strauss syndrome
What are examples of immune complex mediated small vessel vasculitis?
- IgA vasculitis: Henoch-Schonlein purpura (more commonly in children)
- Goodpasture’s (anti-GBM)
What is the general presentation of vasculitis?
- purpura: purple non-blanching spots
- joint and muscle pain
- peripheral neuropathy
- renal impairment
- GI disturbance
- systemic: fever, weight loss, fatigue
How is vasculitis diagnosed?
- CRP and ESR raised
- p-ANCA bloods (Churg-Strauss)
- c-ANCA bloods (Wegner’s)
How is vasculitis managed?
- steroids: oral, IV, nasal, inhaled
- immunosuppressants: cyclophosphamide, methotrexate, azathioprine, rituximab
What is the epidemiology of giant cell arteritis?
- scandanavian
- white
- peak age: 70-80yrs
What is the presentation of giant cell arteritis?
- temporal headache
- visual problems
- scalp tenderness (when brushing hair)
- tongue/jaw claudication
- tenderness + thickening of temporal artery
What key visual problems occur with giant cell arteritis?
- blurring
- veiling
- double vision (diplopia)
- photopsia
- amaurosis fugax
- KEY: irreversible visual loss in one eye
How is giant cell arteritis investigated?
- 1st line: Raised CRP + ESR
- Gold: temporal artery US or biopsy (may be missed due to skip lesions)
- PET-CT for extra cranial disease
How is giant cell arteritis managed?
- oral prednisolone (40-60mg/day)
- IV methylprednisolone
- gradual reduction of steroid over 12-18 months
Describe polyarteritis nodosa?
- occurs in males and with hep B, age 40-60
- can cause renal impairment, stroke, MI
- associated with mottled purple rash: livedo reticularis
How does granulomatosis with polyangitis (Wegner’s) present?
- epistaxis, crusty nasal secretions
- hearing loss and sinusitis
- saddle shaped nose due to perforated septum
- cough, haemoptysis
- glomerulonephritis
What is myositis and what is the difference between polymyositis and dermatomyositis?
- autoimmune skeletal muscle inflammation and necrosis
- polymyositis: chronic muscle inflammation
- dermatomyositis: connective tissue disorder with chronic muscle and skin inflammation
What are the possible causes and epidemiology of myositis?
- underlying malignancy
- lung, breast, ovarian and gastric cancer
- affects females with HLA B8 and HLA DR3 gene
What is the importance of CK in myositis?
- creatine kinase: enzyme released in muscle inflammation
- usually less than 300U/L but is >1000 in disease
- can also be caused by: rhabdomyolysis, AKI, MI, strenuous exercise
How does myositis present?
- muscle pain, fatigue and weakness
- bilaterally, affects proximal muscles
- affects shoulder and pelvic girdle
- onset over weeks
How does dermatomyositis present?
- Gottron lesions on knuckles, elbows, knees
- photosensitive erythematous rash (back, shoulders, neck)
- purple rash on face + eyelids
- periorbital oedema
- calcinosis
Which autoantibodies are seen in myositis?
- Anti-Jo-1: polymyositis
- Anti-Mi-2 antibodies: dermatomyositis
- Anti-nuclear antibodies: dermatomyositis
How is myositis diagnosed?
- clinical presentation
- elevated CK + LDH
- autoantibodies
- electromyography
- muscle biopsy is definitive
How is myositis treated?
- 1st line: corticosteroids
- immunosuppressants (azathioprine)
- IV immunoglobulins
- biological therapy (infliximab)
What is ankylosing spondylitis?
- inflammatory condition of the spine causing progressive stiffness and pain
- part of seronegative spondyloarthropathy conditions
- relates to HLA B27 gene
How does ankylosing spondylitis present?
- lower back pain and stiffness
- sacroiliac pain in buttock
- pain is worse with rest and improves with movement
- worse at night, improves in morning (30+ mins activity
How is ankylosing spondylitis investigated?
- CRP and ESR raised
- HLA B27 raised
- X-ray of spine and sacrum
- spinal MRI shows bone marrow oedema
What is seen on X-ray of ankylosing spondylitis?
- Bamboo spine
- squaring of vertebral bodies
- subchondral sclerosis and erosion
- Syndesmyophytes (bone growth at ligaments)
- ossification of ligaments, discs, joints
- fusion of joints
How is ankylosing spondylitis managed?
- NSAIDs for pain
- steroids
- Anti-TNF: etanercept/infliximab
- Secukinumab (monoclonal antibody against interleukin-17)
What complications is ankylosing spondylitis associated with?
- anterior uveitis
- enthesitis
- dactylitis
- heart block
- restrictive lung disease
- aortitis
What is psoriatic arthritis?
- inflammatory arthritis associated with psoriasis
- occurs in 10-20% of patients with psoriasis
What is arthritis mutilans?
- occurs in phalanxes
- osteolysis of bones around joints in digits
- leads to progressive shortening of finger (telescopic)
What are signs of psoriatic arthritis?
- plaques of psoriasis
- pitting of nails
- onycholysis
- dactylitis
- enthesitis
- inflamed DIP joints
What X-ray changes are seen in psoriatic arthritis?
- periosititis: thickened and irregular outline of bone
- ankylosis: joint stiffening
- osteolysis: destruction of bone
- dactylitis: appears as soft tissue swelling
- pencil-in-cup appearance: central erosions of bones causes one to sit in another